Golf course sand traps, also called “bunkers,” are sand-filled surfaces that are typically installed in areas of native soil and vegetation. Bunkers surfaces are covered with sand that is costly due to the criteria of its selection such as substantially uniform particle size as dictated by USGA standards, particle shape that provides firmness such as angular particles that tend to interlock together for a firm footing, and even aesthetic needs for sand color.
Maintenance of bunker sand is known to be formidable to consistently provide a surface of even thickness that is not too soft, not too hard, not too dry, and not too wet as perceived by golfers. Maintaining the bunker sand requires routine raking of the sand, edging of the grass surrounding the bunker, weed control to prevent contamination of the sand with weeds arising from the underlying native soil, and removal of silt, clay, organic matter, pebbles, and rocks that contaminate the sand as an aging bunker develops inadequate drainage.
Inconsistent moisture content and inadequate drainage may adversely affect playing conditions and may ultimately lead to costly repairs for replacement sand and/or bunker renovation. Natural variations in the native soil under the sand may cause loss of sand into the underlying native soil, pooling of water in portions of the bunker, sand that contains uneven moisture with dry spots and wet spots, and undesirable particles migrating from the native soil into the sand which may cause hazards to golfers and/or maintenance equipment. Blurring of the delineation between the bunker and the surrounding native surface of grass, turf, or native soil, also adversely affects play due to golf rules about what the golfer can and cannot do prior to hitting a ball lying in this junction.